20814865 has 4 divisors (see below), whose sum is σ = 24977844. Its totient is φ = 16651888.

The previous prime is 20814863. The next prime is 20814869. The reversal of 20814865 is 56841802.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3972049 + 16842816 = 1993^2 + 4104^2 .

It is a cyclic number.

It is not a de Polignac number, because 20814865 - 2¹ = 20814863 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20814865.

It is not an unprimeable number, because it can be changed into a prime (20814863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2081482 + ... + 2081491.

It is an arithmetic number, because the mean of its divisors is an integer number (6244461).

Almost surely, 2^20814865 is an apocalyptic number.

It is an amenable number.

20814865 is a deficient number, since it is larger than the sum of its proper divisors (4162979).

20814865 is an equidigital number, since it uses as much as digits as its factorization.

20814865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4162978.

The product of its (nonzero) digits is 15360, while the sum is 34.

The square root of 20814865 is about 4562.3310927639. The cubic root of 20814865 is about 275.0792719126.

The spelling of 20814865 in words is "twenty million, eight hundred fourteen thousand, eight hundred sixty-five".